Method and means for removing carbon deposits



UNITED STATES PATENT OFFICE METHOD AND MEANS FOR REMOVING CARBON DEPOSITS Wheeler G. Lovell and Thomas A. Boyd, Detroit, Mich., assignors to General Motors Research Corporation, Detroit, Micln, a corporation of Delaware No Drawing. Application August 28, 1929 Serial No. 389,089

8 Claims. (01. 8'l-5) This application relates to the removal of carthe carbon deposit diethyl formamide, and rebon deposits from the combustion chambers of moving the carbon deposit. internal combustion engines, and its principal 3. The process of removing carbon deposits objects are to employ compounds particularly from the combustion chamber of an internal suitable for this purpose and a process adapted combustion engine which comprises heating the to employ these compounds at their highest coated parts, applying to the carbon deposit an efliciency. aliphatic amide which removes varnish, and a We have found that aliphatic amides such as low boiling varnish remover, and removing the diethyl formamide and formamide which will carbon deposit. 10 remove varnish are particularly useful in remov- 4. The process of removing carbon deposits ing carbon deposits, and that the best method of from the combustion chamber of an internal using them is to apply them to carbon coated combustion engine which comprises heating the parts which have been heated preferably to a coated parts to above 150 F., applying to the temperature above 150 F., the optimum condicarbon deposit an aliphatic amide which removes 15 tions for water cooled engines being at approxivarnish, benzol and alcohol, and removing the mately the boiling point of water. We may also carbon deposit. use with aliphatic amides a, mixture of benzol and 5. The process of removing carbon deposits alcohol, or other low boiling varnish remover, from the combustion chamber of an internal which apparently increases the solvent action of combustion engine which comprises heating the 0 aliphatic arrides not only by reducing the viscoated parts, applying to the carbon deposit cosity, but also because they are lower boiling and t y formamide, benzol and alcohol. and tend to keep the liquid in contact with the carbon moving the carbon deposit. in a mild state of agitation. 6. The process of removing carbon deposits As a specific example we may use in each from the combustion chamber of an internal comcylinder 01' an ordinary six cylinder engine 30 ust n engine whi pris s h at the 0.0. of a mixture comprising by volume 20 parts a d P s to above pp y g to the of diethyl formamide, 40 parts of benzol, and 40 Carbon p t diethyl formamide, ol and parts of ethyl alcohol. The engine is operated alcohol, and removing the carbon deposit. until the temperature of the metal parts or the '7. A composition of matter for removing car- 30 combustion chamber is at least 150 F. when the bon dep sits f o t a o us n ines mixture is injected or otherwise introduced into comprising an aliphatic de which removes the cylinders and the engine stopped. The mixvarnish, and a low boiling varnish remover. ture is permitted to remain in the cylinders for 8. A composition of matter for removing carabout two hours, more or less, depending upon the bon deposits from internal Combustion engines 35 nature of the carbon deposit, during which time comprising diethyl formamide, benzol and the gummy binder is softened or dissolved. Then alcohol.

the engine is started and the loosened deposit is WHEELER G. LOVELL. gradually blown out the exhaust. THOMAS A. BOYD.

When cleaning the parts by hand they may be heated, the solvent applied, and when the binder is softened the deposit may be wiped 0115.

It is within the scope of the present invention to employ any aliphatic amide which is a varnish remover and to vary the proportions according to 45 the compound used and the specific conditions,

and the aliphatic amide may be used alone.

We claim:- 1. The process of removing carbon deposits from the combustion chamber of an internal combustion engine which comprises applying to the carbon deposit an aliphatic amide which removes varnish, and removing the carbon deposit. 2. The process of removing carbon deposits from the combustion chamber of an internal 5 combustion engine which comprises applying to 

